Objective Nonparametric maximum likelihood estimate(NPMLE)and Breslow-Fleming-Harrington estimate(BFH)are extremely sensitive to small risk set for left truncated and right censored data,this study aims to develop estimation methods to improve the estimation accuracy and compare the existing methods.Methods We introduced the NPMLE,weighted NPMLE,conditional NPMLE,BFH and a new weighted BFH estimate.Simulation studies were carried out to compare five methods via the integrated absolute error(IAE) and integrated average width(IAW).Results The IAE of NPMLE,BFH,weighted NPMLE,weighted BFH and conditional NPMLE is ascending in turn;The IAW of weighted BFH is the lowest and NPMLE is the largest,BFH,conditional NPMLE and weighted NPMLE is reversed under different censored rate.Conclusion According to the results of simulation and example,weighted BFH and weighted NPMLE is recommended in turn when the risk set is small.Otherwise,the results of five methods would be consistent.

Objective: To evaluate the self awareness of professional competencies and its development of teachers for health in primary and secondary schools in Shanghai, so as to provide a reference for development of professional competencies and future specialized development. Methods: A survey was conducted among 1 722 teachers for health in primary and secondary school by the professional competency questionnaire. Results: Most of the teachers for health had bachelor s degrees (65.6%) and junior professional titles (43.4%), the full time teachers accounted for 66.5%, the percentage of teaching health education courses was 69.8 %, 7.7% took part in the formal class of schedule; the two top scorers were the dimension of "professional ethic as a teacher" and "school public health prevention and control" (4.68±0.43, 4.55±0.47); the two lowest scorers dimensions were related to school health education with increasing standard deviation (3.96±0.66, 3.91±0.65); the mean of self rated competency of the 6-14 years working experience group was slightly higher in all dimensions, that of 15 years or above group was lower than 6-14 years group in the total system and the dimensions of professional ethic as a teacher and emergency handling of accidents, and in responsing specific health problems dimension, the mean of 15 years or above group lower than that of 1-5 years group ( P <0.05). Conclusion The entry threshold of teachers for health in primary and secondary school is a critical consideration; Teachers competency preparations are satisfying in professional ethics and school public health prevention/control; meanwhile, the overall health education competencies were insufficient, and noticeable differences in the competency level among teachers are observed. It suggest drawing up entry qualifications and professional standards for health education teachers to guide the teacher s learning and improvement, calling for facilitating the professional promotion of teachers at the government s policy level.

Objective To investigate the clinical utility of keyhole craniotomy for Cholesteatmas in the cerebello-pontine angle region presenting as Trigeminal neuralgia by using keyhole craniotomy. Methods Clinical data of 35 pa-tients with Cholesteatmas in the cerebellopontine angle region presenting as Trigeminal neuralgia was analyzed retrospec-tively. All patients received suboccipital retrosigmoid keyhole craniotomy. Thirty cases who received conventional craniot-omy group were served as control group. A comparative analysis was conducted to assess the difference between these two groups in microsurgical methods, effects and complications. Results All patients were confirmed with MR diagnosis. In keyhole group, all patients had no pain symptoms of trigeminal neuralgia after surgical operation. The symptoms disap-peared immediately in 33 cases and gradually disappeared in 2 cases within one month following keyhole craniotomy. The tumors were totally removed in 25 cases and almost completely in 10 cases. The surgical duration was shorten in key-hole group than in conventional group (126±48 vs. 216±66 min;t=2.536, P<0.05). The amount of bleeding was smaller in keyhole group than in conventional group (91.3±52.2 vs. 186.3±65.4 mL;t=2.163, P<0.05). Postoperative neurologi-cal function was assessed in House-Brackmann. In keyhole group, there were 32 cases in class Ⅰ and 3 in grade Ⅱ. Two patients had hearing loss which was improved gradually in three months. In conventional group, there were 25 cases in class Ⅰ and 5 in grade Ⅱ (χ2=4.158, P<0.05). Postoperative hearing evaluation (AAO-HNS) revealed that there were 33 cases in grade A , and 2 in grade B in the keyhole group, whereas there were 27 cases in grade A and 3 in grade B in the conventional group(χ2=5.167, P<0.05). There were no relapse of tumors and death during 3 month to 5 years follow-up. Conclusions The suboccipital retrosigmoid keyhole craniotomy is a valid choice for Cholesteatmas in the cerebellopontine angle region presenting as Trigeminal neuralgia.

ObjectiveTo investigate an optimal treatment of localized low flow type venous malformation located in the oral and maxillofacial region.MethodsFifty seven patients with localized low-flow venous malformation were treated by intralesional injection of PYM.The injections was repeated at an interval of 10 to 14 days,but not more than 3-5 sessions within a therapeutic period.If necessary,the secondary therapeutic period was performed 1 month later.The general and local adverse responses and the appearance improvement were recorded.The clinical outcomes and aesthetic effects were assessed with a follow-up of 1 to 3 years.ResultsAfter 3-8 injections,complete clinical resolutions were achieved in 52 patients.The deformity disappeared thoroughly.The surface skin and the appearance of lesions showed normal.4 patients received completed lesion control and showed nor mal skin or muco but a little hypertrophy tissue.One venous malformation reduced 2/3 volume after 8injections but improved slowly.The therapeutic time seemed to be related with the size of lesion.Diameter less than 3 cm could be usually cured within 1 treatment period.No ulcerations or scars were presented in injection regions.The function of nerves in oral and maxillofacial region remained normality in all patients.The systematic complication included transient pyrexia and poor appetite appeared in several cases.No allergy was found.No clinical recurrence was observed during the follow-up.ConclusionsTreatment of localized low-flow venous malformations in oral and maxillofacial region with PYM sclerotherapy reveals a high rate of complete clinical resolution,a fair cosmetic and function result,and does not damage facial nerves or form local scars.And it might be regard as an optimal therapeutic method to localized low-flow venous malformations.